A battery stack may be provided by arranging a plurality of cells along one direction. A restraint mechanism may be used to give a restraint force to the plurality of cells. The restraint force refers to a force which tightly holds the plurality of cells in the direction of the arrangement of the plurality of cells.
Specifically, as described in Patent Document 1, a partitioning plate is placed at a position adjacent to a cell, and a protruding portion provided on the partitioning plate is brought into contact with the cell to give a restraint force to the cell from the partitioning plate. The protruding portion is used to form a space between the cell and the partitioning plate for moving a heat exchange medium used in adjusting the temperature of the cell.